patch: use absolute paths for gbp.patch_series classes
patch: use absolute paths for gbp.patch_series classes

We already have a "Patch" class for Tambo in patch.py, and this was
conflicting with gbp's "Patch" class.

Resolve this by simply using the absolute path to all gbp Python
objects.

red-hat-storage/rhcephpkg,red-hat-storage/rhcephpkg